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United States Patent |
6,151,748
|
Earhart, Jr.
,   et al.
|
November 28, 2000
|
Carpeting and surface cleaning apparatus
Abstract
A cleaning device for either carpeted or hard surfaces which utilizes
pressurized cleaning fluid to clean the surface. The fluid nozzles are
arranged on two or more heads which are in turn mounted on two or more
arms. The arms rotate about a common axis causing the heads to move in a
circular pattern. The heads rotate about their own central axis. The
nozzles are angled relative to the surface being cleaned and preferably
rotate towards the direction of the fluid jet. Preferably, at least two of
the heads counter-rotate. Also preferably, the heads are arranged at
somewhat different radial distances from the rotational axis of the arms
so that their coverage patterns partially overlap. The combination of the
counter rotation and the overlap provides an alternating, or beating,
pattern to the angle of incidence of the fluid on the surface being
cleaned. The device may alternatively include vacuum nozzles to retrieve
the cleaning fluid and may incorporate two sets, one to the front and one
to the rear, so that the device may be operated in either direction.
Optionally, manual or automatic switching may be used to activate one set
of nozzles at a time. Additional rinse nozzles may be used to provide
additional rinse fluid immediately adjacent the vacuum nozzles. The rinse
nozzles may also be switched with the vacuum nozzles.
Inventors:
|
Earhart, Jr.; Robert E. (Thornton, CO);
Halls; Kenneth F. (Arvada, CO);
Halls; Grant K. (Boulder, CO)
|
Assignee:
|
Environmental Cleaning Systems, Inc. (Denver, CO)
|
Appl. No.:
|
531928 |
Filed:
|
March 21, 2000 |
Current U.S. Class: |
15/321; 15/322; 239/227 |
Intern'l Class: |
G47L 011/34 |
Field of Search: |
15/320,321,322
239/227
|
References Cited
U.S. Patent Documents
4000538 | Jan., 1977 | Tissier.
| |
4182001 | Jan., 1980 | Krause | 15/320.
|
4191589 | Mar., 1980 | Halls.
| |
4219155 | Aug., 1980 | Goerss | 15/320.
|
4353145 | Oct., 1982 | Woodford.
| |
4369544 | Jan., 1983 | Parisi.
| |
4441229 | Apr., 1984 | Monson | 15/320.
|
4692959 | Sep., 1987 | Monson | 15/320.
|
5133107 | Jul., 1992 | MacDonald.
| |
5367740 | Nov., 1994 | McCray.
| |
5463791 | Nov., 1995 | Roden | 15/320.
|
5587021 | Dec., 1996 | Hoersh.
| |
5784754 | Jul., 1998 | Roden et al. | 15/320.
|
Foreign Patent Documents |
434-907 | Jul., 1991 | EP.
| |
2535-226 | Oct., 1982 | FR.
| |
1567-181 | Feb., 1988 | SU.
| |
Primary Examiner: Moore; Chris K.
Attorney, Agent or Firm: Hanson; Thomas W.
Claims
We claim:
1. A surface cleaning apparatus comprising:
a) supply means for means for supplying pressurized cleaning fluid;
b) a chassis adapted to move over the surface;
c) plural arms, each of said arms:
i) rotatably supported relative to said chassis on an arm axis, and
extending radially from said arm axis, said arm axis substantially
perpendicular to the surface,
ii) having proximal and distal ends, and
iii) comprising a fluid channel for transferring fluid from said proximal
end longitudinally along said arm;
d) fluid coupling means for transferring cleaning fluid from said supply
means to said arms' fluid channels;
e) at least one head attached to each of said arms, each of said heads:
i) rotatably supported relative to said arm on an independent head axis,
ii) comprising at least one fluid nozzle for emitting cleaning fluid onto
the surface, said nozzle directed toward the surface at an inclined angle
to the surface, and
iii) comprising fluid transfer means connected to said nozzle and to said
arm's fluid channel; and
f) mechanical drive means:
i) comprising a motor drive supported by said chassis,
ii) operatively connecting said motor drive to said arms whereby said arms
are driven rotationally about said arm axis,
iii) operatively connecting said motor drive to each of said heads whereby
said head is driven rotationally about its head axis.
2. The cleaning apparatus of claim 1 wherein each of said head axes has a
radial distance from said arm axis and at lease two of said radial
distances are substantially different.
3. The cleaning apparatus of claim 1 wherein the rotational motion of said
heads is such that said nozzles move generally in the direction of said
inclined angle.
4. The cleaning apparatus of claim 3 wherein at least two of said heads
rotate in opposing directions.
5. The cleaning apparatus of claim 4 wherein each of said head axes has a
radial distance from said arm axis and at least two of said radial
distances are substantially different.
6. The cleaning apparatus of claim 5 wherein each of said heads defines a
coverage pattern as it moves and said two radial distances are
sufficiently similar that said coverage patterns overlap substantially,
whereby that portion of the surface in the overlapping area is subjected
to cleaning fluid at alternating angles.
7. The cleaning apparatus of claim 1 wherein said motor drive comprises a
variable speed control.
8. The cleaning apparatus of claim 1 wherein said cleaning fluid supply
means comprises a variable fluid pressure control.
9. The cleaning apparatus of claim 1 further comprising a vacuum nozzle,
supported by said chassis, coupled to a vacuum pump, and adapted to be in
close proximity to the surface, whereby said vacuum nozzle extracts
cleaning fluid emitted by said nozzles.
10. The cleaning apparatus of claim 9 further comprising a second vacuum
nozzle coupled to said vacuum source and wherein said chassis is adapted
to travel in a substantially linear direction, said first and second
vacuum nozzles being opposed by 180 degrees relative to said arm axis and
positioned so that one precedes said arms and one follows said arms as
said chassis moves linearly.
11. The cleaning apparatus of claim 10 further comprising means to select
between said first and second vacuum nozzles for coupling to said vacuum
source.
12. The cleaning apparatus of claim 11 wherein said means to select
automatically selects one of said vacuum nozzles based on the relative
direction of movement of said chassis.
13. The cleaning apparatus of claim 11 wherein said means to select
automatically selects one of said vacuum nozzles and one set of said rinse
nozzles based on the relative direction of movement of said chassis.
14. The cleaning apparatus of claim 10 further comprising a first and
second set of rinse nozzles, said first set adapted to emit fluid adjacent
said first vacuum nozzle between said first vacuum nozzle and said arms,
said second set adapted to emit fluid adjacent said second vacuum nozzle
between said second vacuum nozzle and said arms.
15. The cleaning apparatus of claim 14 further comprising means to select
between said first and second vacuum nozzles for coupling to said vacuum
source and between said first and second set of rinse nozzles for emitting
fluid.
16. A surface cleaning apparatus comprising:
a) supply means for means for supplying pressurized cleaning fluid;
b) a chassis adapted to move over the surface;
c) plural arms, each of said arms:
i) rotatably supported relative to said chassis on an arm axis, and
extending radially from said arm axis, said arm axis substantially
perpendicular to the surface,
ii) having proximal and distal ends, and
iii) comprising a fluid channel for transferring fluid from said proximal
end longitudinally along said arm;
d) fluid coupling means for transferring cleaning fluid from said supply
means to said arms' fluid channels;
e) at least one head attached to each of said arms, each of said heads:
i) rotatably supported relative to said arm on an independent head axis,
ii) comprising at least one fluid nozzle for emitting cleaning fluid onto
the surface, said nozzle directed toward the surface at an inclined angle
to the surface, and
iii) comprising fluid transfer means connected to said nozzle and to said
arm's fluid channel;
wherein at least two of said heads rotate in opposing directions;
f) mechanical drive means:
i) comprising a motor drive supported by said chassis,
ii) operatively connecting said motor drive to said arms whereby said arms
are driven rotationally about said arm axis,
iii) operatively connecting said motor drive to each of said heads whereby
said head is driven rotationally about its head axis; and
g) a vacuum nozzle, supported by said chassis, coupled to a vacuum pump,
and adapted to be in close proximity to the surface, whereby said vacuum
nozzle draws up cleaning fluid emitted by said nozzles.
17. The cleaning apparatus of claim 16 wherein each of said head axes has a
radial distance from said arm axis and each of said heads defines a
coverage pattern as it moves and wherein at least two of said radial
distances are sufficiently different that said coverage patterns overlap
by no more than 90 percent and said two radial distances are sufficiently
similar that said coverage patterns overlap by no less than 10 percent,
whereby that portion of the surface in the overlapping area is subjected
to cleaning fluid at alternating angles.
18. The cleaning apparatus of claim 17 further comprising a second vacuum
nozzle coupled to said vacuum source and wherein said chassis is adapted
to travel in a substantially linear direction, said first and second
vacuum nozzles being opposed by 180 degrees relative to said arm axis and
positioned so that one precedes said arms and one follows said arms as
said chassis moves linearly and means to select between said first and
second vacuum nozzles for coupling to said vacuum source.
19. The cleaning apparatus of claim 18 wherein said means to select
automatically selects one of said vacuum nozzles based on the relative
direction of movement of said chassis.
20. The cleaning apparatus of claim 19 further comprising a first and
second set of rinse nozzles, said first set adapted to emit fluid adjacent
said first vacuum nozzle between said first vacuum nozzle and said arms,
said second set adapted to emit fluid adjacent said second vacuum nozzle
between said second vacuum nozzle and said arms and wherein said means to
select also selects between said first and second set of rinse nozzles for
emitting fluid.
Description
FIELD OF THE INVENTION
The present invention relates to cleaning devices for floors and other
surfaces, especially such devices which use a pressurized cleaning fluid
to effect the cleaning.
BACKGROUND OF THE INVENTION
Carpet cleaning systems of the general configuration of the present
invention are well known. The use of a separate base and mobile unit is
common as it reduces the weight of the mobile unit which the user must
manipulate. Many such systems, however, rely on brushes or fixed cleaning
nozzles to do the actual cleaning. The use of fixed nozzles is effective,
but limited in that a particular spot on the carpet is typically treated
only a single time, by a single nozzle.
A previous patent, U.S. Pat. No. 4,191,589 to Halls et al discloses a
mobile unit comprising rotating arms with fixed nozzles positioned at the
ends of the arms. That system improves on the fixed nozzle systems in that
a particular spot will be addressed many times as the nozzles rotate past.
The rotary motion of the arms is imparted by the force of the cleaning
fluid exiting the nozzles. As such, the arm rotates in a direction away
from the direction of the cleaning fluid jet. One embodiment of the system
comprised a single nozzle which pointed in the direction of rotation. Its
force then has to be overcome by the force of the remaining jets so that
the arm will rotate. That system also incorporates a vacuum pickup at the
front edge, supplemental rinse nozzles positioned behind the vacuum
pickup, and a base unit comprising the vacuum and pressure pump
subsystems. The use of fluid pressure at the nozzles to impart the rotary
motion is convenient and advantageous in that the unit can be made much
lighter since no mechanical drive train is required. However, the
efficiency of the cleaning is compromised. A majority of the jets must
move away from the direction of the fluid jet, reducing their
effectiveness. The fluid pressure and nozzle angles must be selected so as
to impart the desired rotational speed. The arm, and nozzles, are in
motion only when cleaning fluid is being emitted. A "spin up" delay is
required when the cleaning fluid is activated to allow the arm to attain
its rotation speed, During this delay, cleaning ability is compromised,
and it may be necessary to hold the unit in a stationary position, wasting
cleaning fluid, time, and possibly over exposing the surface to cleaning
fluid, leading to saturation.
Windsor Industries Inc., Englewood, CO has reportedly sold a cleaning
system in which a motor drive is used to rotate an arm with a set of fixed
heads in the direction of the fluid jet. This design overcomes some of the
problems of the pressure driven system but still falls short of an ideal
system. All of the jets in this system point in the same direction and
rotate in the same direction. Further, the coverage pattern is a simple
circular one which can lead to skips and striping.
Various types of rotary brush floor cleaners are also well known. These are
typically designed for use on hard surfaced floors. While usable on
certain short-napped carpets, they are not generally applicable to
carpeted surfaces.
There is a need for a cleaning system which utilizes pressurized cleaning
fluid applied from a series of rotating nozzles wherein the motion of the
nozzles and the pressure and angle of the cleaning fluid jets are not
interrelated. The nozzles should travel in a complex pattern such as that
provided by rotating heads mounted to a separately rotating arm.
Preferably the pressure at which the fluid is emitted and the angle at
which it is emitted can be varied without effecting the rotational speed
of the supporting arm. Preferably, the nozzles will move in the same
direction in which the cleaning jet is emitted, rather than away from it.
Ideally, plural heads will be provided which rotate in opposite
directions, providing alternating directions for the fluid jet. Ideally,
fluid pressure and temperature, rotational speed, and nozzle angle can all
be adjusted by the end user of the system, either via a control on the
base unit, remote wireless or corded control on the mobile unit, or by
interchanging components of the system. Such a system should be usable on
a variety of surface including carpeted and hard surfaced floors
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus for cleaning either
carpeted or hard surfaces. The apparatus utilizes multiple nozzles on
rotating head which are in turn mounted on rotating arms. The rotation of
the arms and the heads is mechanically driven, independently of the fluid
pressure. In the preferred embodiment, the heads rotate in the direction
of the fluid jet and at least two of the heads counter-rotate.
According to the invention there is provided a chassis supporting plural
arms, each arm supporting at least one head, each head having at least one
nozzle. A fluid supply subsystem provides pressurized cleaning fluid to
the nozzles by way of the arms and heads. A mechanical drive system uses a
motor to rotate the arms about a common axis and to rotate the heads
around their own central axis.
According to an aspect of the invention at least two of the heads are
positioned at a different distance from the axis about which the arms
rotate, providing a partially overlapping coverage pattern.
According to another aspect of the invention the heads rotate in the
direction of the fluid jet and, further, at least two of the heads counter
rotate.
Further in accordance with the invention either, or both, of the motor
speed and the fluid pressure are variable.
Still further in accordance with the invention, a vacuum subsystem is
provided to recover the cleaning fluid. It may use a single set of nozzles
at the front end, or may also include a second set at the back end. Where
two sets are used, switching may be provided to activate only one set at a
time, and this switching may be automatic, dependent on the direction of
movement.
Still further in accordance with the invention, rinse nozzles may be
provided adjacent the vacuum nozzles to provide additional, possibly
clean, fluid. Switching of the nozzles may also be provided and may be
automated.
The advantages of such an apparatus are that a pressurized fluid cleaning
system is provided in which rotating heads, in combination with rotating
arms, provide a complex and more thorough coverage pattern than is
possible without the rotating heads. Where the heads counter-rotate, the
system provides an alternating pressure pattern which physically beats the
surface, and dirt, resulting in more effective cleaning than where a
single direction is used. The rotational speeds and fluid pressure are
variable, allowing the system to be configured to a wide variety of
surfaces and soil conditions.
The above and other features and advantages of the present invention will
become more clear from the detailed description of a specific illustrative
embodiment thereof, presented below in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the components of the complete system.
FIG. 2 is a cross section through the mobile unit.
FIG. 3 provides a top view of the mobile unit with the cover removed.
FIG. 4 provides a front view of the mobile unit with the cover removed.
FIG. 5 is a top view of the arm and heads with the cover cut away to show
the drive mechanism.
FIG. 6 is a bottom view of the arm and heads with the cover cut away to
show the drive mechanism.
FIG. 7 is a side view of the arm, heads, and drive train with the cover cut
away.
FIG. 8 illustrates the coverage pattern of the heads.
FIGS. 9A & B illustrate the alternating jet angles provided by the opposing
rotation of the heads.
FIG. 10 illustrates the motion of the nozzle in the direction of the jet.
FIG. 11 illustrates the PRIOR ART motion of a nozzle away from the
direction of the jet.
DETAILED DESCRIPTION OF THE INVENTION
The following discussion focuses on the preferred embodiment of the
invention, as a carpet cleaner. However, as will be recognized by those
skilled in the art, the disclosed apparatus is applicable to a wide
variety of situations in which surface cleaning using a cleaning fluid is
desired.
The following is a brief glossary of terms used herein. The supplied
definitions are applicable throughout this specification and the claims
unless the term is clearly used in another manner.
Arm--generally the rotating portion of the mobile unit which supports the
heads. In the preferred embodiment a single unit it used which comprises
two opposed arms. Unless clearly used otherwise, "arm" in intended to
encompass any structure comprising plural arms extending outward from a
single axis.
Base Unit--that portion of the system containing the fluid tanks, pressure
pump, optional fluid heater, and vacuum pump. While movable, it typically
remains stationary while the mobile unit is used to clean the floor. It
will be moved from location to location, or room to room, as necessary to
allow the mobile unit to reach the entire area to be cleaned.
Cleaning Fluid--the fluid used by the system to clean the surface.
Typically this would be water to which a detergent solution has been
added. However, use of clean water, degreasers, solvents, and other
cleaning solutions is anticipated. Use of compressed air, or other gas,
either with or without another entrained component is also anticipated.
Coverage pattern--the area of the surface to be cleaned which is wetted as
the component in question is activated. There are coverage patterns for
the nozzles, heads, and the combined arm/head unit. Most typically,
coverage pattern refers to the coverage pattern of the nozzles on the head
as it rotates about its axis and that axis is rotated about the central
shaft as the arm rotates. A second coverage pattern of importance is
generated as the central shaft is then linearly translated as the mobile
unit is moved.
Fan angle--herein, generally the angular coverage pattern of a jet as it is
emitted form the nozzle. Narrow angles provide greater impact and wider
angles provide greater coverage, for the same fluid pressure.
Floor--used herein as a generic term to refer to that surface being cleaned
by the present invention. While the invention would most frequently be
used with carpeted floors, use of the invention with hard surfaced floors,
paved surfaces, countertops and various other surfaces is anticipated. The
present design can be readily embodied in a smaller handheld unit adapted
for use with smaller, or enclosed, areas.
Front, Rear--"Front" refers to the end of the mobile unit furthest from the
user. "Rear" is the end nearest the user. In use, the unit is typically
pulled toward the user, resulting in the front being the last portion of
the unit to pass over the surface being cleaned.
Head--generally one of the rotating heads located at the distal end of the
arm.
Jet--generally describes the high pressure stream of cleaning fluid emitted
by a nozzle. May also be referred to as a fluid jet.
Mobile Unit--that portion of the system which is moved across the floor by
the user to effect the cleaning operation.
Nozzle--generally a short tube terminating in an opening designed to emit a
jet of cleaning fluid.
Preferred Embodiment
The disclosed invention is described below with reference to the
accompanying figures in which like reference numbers designate like parts.
Generally, numbers in the 100's refer components of the disclosed
invention. Numbers in the 200's are used to refer to other parts of the
system with which the present invention is used, or to objects in the
surrounding environment.
The present invention is an improvement to a cleaning system of the type
illustrated in FIG. 1. This type of system is typically used for cleaning
carpets, but is also applicable to other types of floors, countertops,
driveways, parking lots, or almost any other essentially smooth surface.
The base unit, 200, is a portable unit which includes supply tanks for the
cleaning fluid and additives (if any); a waste recovery tank; a pressure
pump; and a vacuum pump. Alternatively, a connection to a supply source,
such as a faucet, could be used in place of the supply tank. Injection of
a detergent or other additives could be used with either the supply source
connection or with a supply tank filled with otherwise clean fluid. The
pressure pump provides high pressure cleaning fluid, through hose, 204, to
the mobile unit, 100, as is well known in the art. Preferably, the output
pressure of the pump is variable. This may be controlled at the base unit
or by a wired or wireless remote control on the mobile unit. The cleaning
fluid may also be heated with the temperature controlled in a similar
manner. The vacuum pump draws air from the mobile unit, through hose, 202,
as is also well known in the art. The resultant combination is a self
contained system which applies a cleaning fluid to the surface to be
cleaned and then recovers the fluid, leaving the surface substantially
free of cleaning fluid. The base unit is portable and can be moved from
room to room, or to location to location within a larger room, but
typically remains stationary while an area is cleaned with the mobile
unit. The mobile unit is moved over the surface to be cleaned in order to
effect the cleaning. Typically, the mobile unit is pulled backward by the
user while cleaning, and then rolled forward for repositioning. The
backward movement results in the vacuum nozzles, 102, passing over the
cleaned surface immediately after the cleaning nozzles. The rearward and
upward pull on the handle, 104, also lifts the rear of the unit slightly,
resulting in a transfer of weight to the front of the unit, applying an
increased downward force on the vacuum nozzles, increasing their
efficiency. Valve, 106, is activated by the user to regulate the flow of
cleaning fluid to the cleaning nozzles, and optionally to the auxiliary
rinse nozzles, as discussed below. The general configuration of the
cleaning system is conventional and is well known in the art. The novel
aspects of the present invention relate to the configuration and operation
of the mobile unit as discussed below.
Structure
The structure of the mobile unit is shown in more detail in FIGS. 2-4.
Chassis, 108, provides the main structure for the unit as well as
enclosing and shielding the rotating arms and heads which do the actual
cleaning. Wheels, 110, and handle, 104, attach to the chassis in a
conventional manner. Vacuum nozzles, 102, are positioned at the front end
of the unit and connect to the hose from the base unit via pipes, 112.
Optional rinse nozzles, 114, apply extra cleaning fluid to the surface
closely adjacent the vacuum nozzles to aid in rinsing the surface. If
preferred, the rinse nozzles can be provided clean fluid, such as water,
without detergent or other cleaning additives.
The novel aspect of the present invention is embodied in the configuration
and operation of the arm, 116, and heads, 118A&B. The arm rotates around
shaft, 120, carrying the heads in a circular path. The heads also rotate
around their respective shafts, 122A&B, generating a circular spray
pattern. Both the arm and the heads rotate substantially parallel to the
surface being cleaned. Heads 118A and 118B are at different radial
distances from the shaft, 120. This configuration results in a partially
overlapping coverage pattern as shown in FIG. 8. When combined with the
linear movement of the mobile unit the result is a complex coverage
pattern of the surface being cleaned. While beneficial in that it prevents
streaking or striping, the overlapping pattern is not required as the
linear movement of the unit will result in both heads covering all parts
of the surface. Rotary union, 126, transfers pressurized cleaning fluid
from supply hose, 124, to the internal passage of hollow shaft, 120. The
passage then transmits the fluid to passage, 130, which runs lengthwise
through the arm, supplying the fluid to rotary unions, 128A&B. These
unions then transfer the cleaning fluid to the internal passages of hollow
shafts, 122A&B. These shafts then supply the fluid to the heads 118A&B,
for application to the surface to be cleaned. Clearly, an external hose,
or other means, is equivalent to the internal channel. Similarly, other
rotary fluid coupling devices are equivalent to the rotary unions. Cover,
132, encloses the arm and drive components (discussed below) to minimize
their exposure to the cleaning fluid and dirt, and to provide an increased
margin of safety for the operator.
In the preferred embodiment, a single structure, 116, is used to provide
two opposed arms to carry the cleaning heads. It is anticipated that three
or more arms, and heads, could also be used. This would allow for
increased flexibility in selecting radial distances to the heads, for
different coverage patterns, and would allow rotation rates, nozzle
angles, rotation speeds, and other characteristics to be altered and
intermixed with greater variety.
The use of rotating arms in cleaners which are driven by the force of the
cleaning fluid ejected from the nozzles in known in the art. The present
invention differs in that the arms and nozzles are mechanically driven,
independently of the water pressure and direction. This offers significant
benefits in the operation and performance of the unit, not the least of
which is that the nozzles can be driven towards the direction of the jet
rather than retreating from it, as shown in FIG. 10. This increases the
effectiveness of the cleaning and can provide a lifting action as the
cleaning fluid penetrates under the dirt. As the nozzles move in the
direction of the cleaning fluid jet, the fluid first impacts dirt, 208,
(especially caked on accumulations) at the lower edge, where it contacts
the floor, 206. The high pressure of the fluid can then force the fluid
between the dirt and the surface, separating and lifting the dirt. Where
the surface is carpeted, the fluid can penetrate the pile of the carpet
and lift the dirt from below. The typical prior art approach, shown in
FIG. 11 causes the fluid jet to first impact the dirt on the upper surface
rather than at the lower edge. The dirt is forced downward against the
floor possibly causing it to adhere more firmly. While the preferred
embodiment utilizes rotating heads on the ends of the arms, the above
benefits can also be realized with fixed heads attached to the arms, where
the arms are driven in the direction of the cleaning jet.
The drive train for the arm and heads can be seen clearly with reference to
FIGS. 5-7. Motor, 134, drives the central shaft, 120, via pulleys, 136 and
138. In the preferred embodiment these are cogged to eliminate problems of
slippage if the pulleys and belt become wet. Clearly non-cogged belts,
chain drive, or other equivalent means could be used. Shaft, 120, in turn
directly drives arm, 116, at the same rotational rate, causing it to spin
about the shaft in the direction of arrow, 152. Pulley, 140, and gear,
142, are interconnected and fixed to the chassis, remaining stationary. As
gear, 144, rotates around gear, 142, it rotates in the direction of arrow,
156. This rotary motion is transmitted to head, 118A, via shaft, 122A.
Belt, 148, connects pulley, 140, to pulley, 146, causing it to rotate in
direction of arrow, 154. Again, this rotary motion is transmitted to head,
118B, via shaft, 122B. The result of this combination of gear and belt
drive for the two heads is that they rotate in opposite directions. As
discussed below, this offers significant advantages in the operation and
effectiveness of the unit. In the preferred embodiments the various gears
and pulleys are selected so that the heads rotate at the same speed which
is reduced from the speed of the motor. Clearly other combinations of gear
and pulley ratios could be selected to provide other speeds and even to
drive the heads at different speeds if desired.
There are at least two additional benefits of the above mechanical drive
for the arm and heads. The first is in the selection of the rotational
speeds for the arm and the heads. In prior art systems which are driven by
the force of the cleaning fluid emitted from the nozzles, the speed of the
arm and heads is directly related to the pressure of the fluid and the
angle of the nozzles. Altering either characteristic will alter the
rotational speeds. As such, the pressures and angles are compromises,
optimal for neither the rotational speeds nor for cleaning of the surface.
The present mechanical drive removes this dependency and allows the
rotational speeds, fluid pressure, and nozzle angles to be selected
independently. The speeds can be optimized for coverage, vibration,
bearing life and other factors. Fluid pressure and nozzle angle can be
optimized for cleaning. If desired both the motor speed and fluid pressure
can be made variable and controllable by the user. Nozzle angle can also
be varied either by adjusting the angle of the nozzles relative to the
heads or by interchanging the heads. In the preferred embodiment, the
nozzle angles are fixed relative to the head, and heads are interchanged
to provide different angles. This provides stricter control of the angle,
which is critical to the cleaning effectiveness and which should be
matched to the surface (carpet, linoleum, asphalt, etc.) and condition
(lightly soiled, grease caked, etc.). Additionally, different nozzles can
be fitted to alter the fan angle at which the fluid is emitted from a
narrow stream to a relatively wide fan. This further varies the impact of
the fluid on the surface being cleaned. High pressure, combined with
narrow fan angles, and/or slow rotational speeds allow the unit to
physically remove heavy deposits of dirt or grease or even to strip
finishes from certain surfaces. It is also possible to intermix the fan
angles on the various nozzles to provide varied coverage. This can assist
in avoiding striping, streaking, or other patterns which may be created by
the regular pattern of identical jets passing over the surface.
A second benefit of the mechanical drive is that the rotational speeds
remain constant as fluid pressure varies or is activated and deactivated.
In prior art systems, the heads and arm would slow or even stop rotating
when the fluid is switched off as it would at the end of a pass or to
pause to move cords and hoses. After the fluid is switched back on, there
is a delay as the arm and heads spin back up to operational speed. In the
present invention, the rotational movement is independently controlled and
can be maintained at a consistent speed throughout the operation of the
unit.
The characteristic of the heads rotating in opposite directions also
provides a significant benefit. As shown in FIGS. 9A and 9B, as heads,
118A and 118B, pass over the same point on the surface, their nozzles,
158A and 158B, direct the cleaning fluid such that it impacts the surface,
204, (carpet illustrated) from opposite angles. In the preferred
embodiment, the heads are configured so that these angles are symmetric
about the vertical axis. Other combinations could clearly be used. As the
heads pass over, the alternating jet angles provide a beating action to
the surface. This is visible with carpet as the fibers are agitated,
physically helping to loosen the dirt better than can a cleaner with a
single angle. This beating is also effective on smoother surface where
dirt, especially that which is caked on, is impacted from alternating
directions, helping to loosen it.
Functionality
In use, the mobile unit is typically moved forward to the limit of the area
to be cleaned and positioned at the end of an uncleaned strip of floor.
The cleaning jets are then activated and the mobile unit is pulled
backward at a steady pace until the opposite limit of the area is reached.
The cleaning jets are deactivated shortly before the rearward motion is
stopped to assure that the vacuum nozzles cover all of the area wetted by
the jets. Typically the vacuum system and mechanical drive for the arm and
heads remains active throughout the cleaning process. Alternatively, each
could be activated and deactivate in a manner similar to that for the
jets.
As the unit is pulled rearward, each section of floor which passes
underneath is exposed to a series of cleaning jets as the arm and the
nozzles rotate. The counter rotating motion of the heads results in
cleaning fluid impacting the same spot on the floor from alternating
directions, beating and loosening the dirt. The number of times which a
particular spot is exposed to the jets depends on the rotational speeds of
the arms and head and the linear speed of the mobile unit as it is pulled
to the rear. All of these speeds can be varied, either by the user, or in
the manufacturing process.
Alternative Embodiments
The preferred embodiment of the mobile unit utilizes a single vacuum pick
up on the front of the unit. Alternatively, a second vacuum pickup can be
added to the rear of the unit. This allows the unit to be used while
moving forward. This increases the flexibility of the unit by allowing it
to clean while moving in both directions. This can be used to eliminate
the lost time as the unit is moved forward to the limit of the area to be
cleaned. It also allows the unit to be operated in a manner analogous to a
lawn mower, where it is moved forward continuously, and cleans
continuously. While not a major advantage for cleaning interior floors,
this feature becomes significant for cleaning sidewalks and parking lots
as discussed below. If desired, a switch, or valve, could be provide to
select either the front or the rear pickups, reducing the vacuum capacity
which would be required if both were activated simultaneously. A further
alternative is to automatically switch which nozzle is active depending on
the direction of motion of the unit. The second vacuum nozzle could also
be supplemented by a separate set of rinse nozzles analogous to those for
the front nozzle. If desired, these rinse nozzles could be switched in
tandem with the vacuum nozzles. Clearly, the unit could also be built with
a single, rear vacuum pick up.
Another alternative is to fit the heads with brushes. These may either
supplement or replace one or more heads. As a supplement, the brushes may
be formed in a ring around the head, adapted so that the bristles contact
the floor at, or outside of, the point that the cleaning jets impact the
floor. As a replacement, one head can be replaced with a brush, while the
other remains and functions as above. Either way, the brush would be
driven by the same mechanism as the head and would supplement the cleaning
action of the jets with a physical scrubbing action.
A further alternative is to reduce the size of the unit and make it
portable. This portable unit could use a reduced size version of the above
arm and nozzles, or could utilize a single head. With a reduced size arm,
there would still be at least two counter rotating heads, Where a single
head is used, it would be mechanically driven in the direction of the
cleaning jets.
Applicability
The primary application for the present invention is for cleaning carpeted
floors, as much of the prior art systems are used. However, the
applicability of the system is much wider than that. The invention also
shows significant benefit in cleaning hard surfaced floors. Because the
rotational speeds of the arm and the heads are independent of the cleaning
fluid pressure and jet angles, a wide variety of cleaning characteristics
can be achieved. A combination of low pressure and relatively high
rotational speeds provides rapid, low impact cleaning of lightly soiled
surfaces. Conversely, a combination of high pressure and low rotational
speeds, especially if combined with nozzles producing narrow fan angles,
provides a cleaning system with a very high impact on the surface. Such a
configuration is capable of removing heavy soil accumulations and even
stripping certain types of finishes. Where combined with heated cleaning
fluid and strong detergents or solvents, the system is even capable of
cleaning driveways, parking lots, and sidewalks. The vacuum pickup
provides for recovery of the contaminated fluid rather than allowing it to
drain into the sewers. Where parking lots and driveways are being cleaned,
the cleaning fluid is will likely be contaminated with substances such as
oil, gas, and additives such as MTBE, which are hazardous and pose a
significant threat to the environment if flushed into storm sewers or
allowed to run off. The portable version is also applicable to counter
tops, stairs, and other restricted access areas which would benefit from
the cleaning capabilities provided by the present design.
While the preferred form of the invention has been disclosed above,
alternative methods of practicing the invention are readily apparent to
the skilled practitioner. The above description of the preferred
embodiment is intended to be illustrative only and not to limit the scope
of the invention.
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